2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
26 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
27 *root
, struct btrfs_path
*path
, int level
);
28 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
29 *root
, struct btrfs_key
*ins_key
,
30 struct btrfs_path
*path
, int data_size
, int extend
);
31 static int push_node_left(struct btrfs_trans_handle
*trans
,
32 struct btrfs_root
*root
, struct extent_buffer
*dst
,
33 struct extent_buffer
*src
, int empty
);
34 static int balance_node_right(struct btrfs_trans_handle
*trans
,
35 struct btrfs_root
*root
,
36 struct extent_buffer
*dst_buf
,
37 struct extent_buffer
*src_buf
);
38 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
39 struct btrfs_path
*path
, int level
, int slot
);
41 inline void btrfs_init_path(struct btrfs_path
*p
)
43 memset(p
, 0, sizeof(*p
));
46 struct btrfs_path
*btrfs_alloc_path(void)
48 struct btrfs_path
*path
;
49 path
= kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
51 btrfs_init_path(path
);
57 void btrfs_free_path(struct btrfs_path
*p
)
59 btrfs_release_path(NULL
, p
);
60 kmem_cache_free(btrfs_path_cachep
, p
);
63 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
67 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
72 btrfs_tree_unlock(p
->nodes
[i
]);
75 free_extent_buffer(p
->nodes
[i
]);
80 struct extent_buffer
*btrfs_root_node(struct btrfs_root
*root
)
82 struct extent_buffer
*eb
;
83 spin_lock(&root
->node_lock
);
85 extent_buffer_get(eb
);
86 spin_unlock(&root
->node_lock
);
90 struct extent_buffer
*btrfs_lock_root_node(struct btrfs_root
*root
)
92 struct extent_buffer
*eb
;
95 eb
= btrfs_root_node(root
);
98 spin_lock(&root
->node_lock
);
99 if (eb
== root
->node
) {
100 spin_unlock(&root
->node_lock
);
103 spin_unlock(&root
->node_lock
);
105 btrfs_tree_unlock(eb
);
106 free_extent_buffer(eb
);
111 static void add_root_to_dirty_list(struct btrfs_root
*root
)
113 if (root
->track_dirty
&& list_empty(&root
->dirty_list
)) {
114 list_add(&root
->dirty_list
,
115 &root
->fs_info
->dirty_cowonly_roots
);
119 int btrfs_copy_root(struct btrfs_trans_handle
*trans
,
120 struct btrfs_root
*root
,
121 struct extent_buffer
*buf
,
122 struct extent_buffer
**cow_ret
, u64 new_root_objectid
)
124 struct extent_buffer
*cow
;
128 struct btrfs_key first_key
;
129 struct btrfs_root
*new_root
;
131 new_root
= kmalloc(sizeof(*new_root
), GFP_NOFS
);
135 memcpy(new_root
, root
, sizeof(*new_root
));
136 new_root
->root_key
.objectid
= new_root_objectid
;
138 WARN_ON(root
->ref_cows
&& trans
->transid
!=
139 root
->fs_info
->running_transaction
->transid
);
140 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
142 level
= btrfs_header_level(buf
);
143 nritems
= btrfs_header_nritems(buf
);
146 btrfs_item_key_to_cpu(buf
, &first_key
, 0);
148 btrfs_node_key_to_cpu(buf
, &first_key
, 0);
150 first_key
.objectid
= 0;
152 cow
= btrfs_alloc_free_block(trans
, new_root
, buf
->len
,
154 trans
->transid
, first_key
.objectid
,
155 level
, buf
->start
, 0);
161 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
162 btrfs_set_header_bytenr(cow
, cow
->start
);
163 btrfs_set_header_generation(cow
, trans
->transid
);
164 btrfs_set_header_owner(cow
, new_root_objectid
);
165 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
);
167 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
168 ret
= btrfs_inc_ref(trans
, new_root
, buf
);
174 btrfs_mark_buffer_dirty(cow
);
179 int __btrfs_cow_block(struct btrfs_trans_handle
*trans
,
180 struct btrfs_root
*root
,
181 struct extent_buffer
*buf
,
182 struct extent_buffer
*parent
, int parent_slot
,
183 struct extent_buffer
**cow_ret
,
184 u64 search_start
, u64 empty_size
)
187 struct extent_buffer
*cow
;
190 int different_trans
= 0;
193 struct btrfs_key first_key
;
198 WARN_ON(!btrfs_tree_locked(buf
));
200 if (root
->ref_cows
) {
201 root_gen
= trans
->transid
;
205 WARN_ON(root
->ref_cows
&& trans
->transid
!=
206 root
->fs_info
->running_transaction
->transid
);
207 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
209 level
= btrfs_header_level(buf
);
210 nritems
= btrfs_header_nritems(buf
);
213 btrfs_item_key_to_cpu(buf
, &first_key
, 0);
215 btrfs_node_key_to_cpu(buf
, &first_key
, 0);
217 first_key
.objectid
= 0;
219 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
,
220 root
->root_key
.objectid
,
221 root_gen
, first_key
.objectid
, level
,
222 search_start
, empty_size
);
226 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
227 btrfs_set_header_bytenr(cow
, cow
->start
);
228 btrfs_set_header_generation(cow
, trans
->transid
);
229 btrfs_set_header_owner(cow
, root
->root_key
.objectid
);
230 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
);
232 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
233 if (btrfs_header_generation(buf
) != trans
->transid
) {
235 ret
= btrfs_inc_ref(trans
, root
, buf
);
239 clean_tree_block(trans
, root
, buf
);
242 if (buf
== root
->node
) {
243 WARN_ON(parent
&& parent
!= buf
);
244 root_gen
= btrfs_header_generation(buf
);
246 spin_lock(&root
->node_lock
);
248 extent_buffer_get(cow
);
249 spin_unlock(&root
->node_lock
);
251 if (buf
!= root
->commit_root
) {
252 btrfs_free_extent(trans
, root
, buf
->start
,
253 buf
->len
, root
->root_key
.objectid
,
256 free_extent_buffer(buf
);
257 add_root_to_dirty_list(root
);
259 root_gen
= btrfs_header_generation(parent
);
260 btrfs_set_node_blockptr(parent
, parent_slot
,
262 WARN_ON(trans
->transid
== 0);
263 btrfs_set_node_ptr_generation(parent
, parent_slot
,
265 btrfs_mark_buffer_dirty(parent
);
266 WARN_ON(btrfs_header_generation(parent
) != trans
->transid
);
267 btrfs_free_extent(trans
, root
, buf
->start
, buf
->len
,
268 btrfs_header_owner(parent
), root_gen
,
272 btrfs_tree_unlock(buf
);
273 free_extent_buffer(buf
);
274 btrfs_mark_buffer_dirty(cow
);
279 int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
280 struct btrfs_root
*root
, struct extent_buffer
*buf
,
281 struct extent_buffer
*parent
, int parent_slot
,
282 struct extent_buffer
**cow_ret
)
288 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
289 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
290 root
->fs_info
->running_transaction
->transid
);
293 if (trans
->transid
!= root
->fs_info
->generation
) {
294 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
295 root
->fs_info
->generation
);
299 header_trans
= btrfs_header_generation(buf
);
300 spin_lock(&root
->fs_info
->hash_lock
);
301 if (header_trans
== trans
->transid
&&
302 !btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_WRITTEN
)) {
304 spin_unlock(&root
->fs_info
->hash_lock
);
307 spin_unlock(&root
->fs_info
->hash_lock
);
308 search_start
= buf
->start
& ~((u64
)(1024 * 1024 * 1024) - 1);
309 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
310 parent_slot
, cow_ret
, search_start
, 0);
314 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
316 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
318 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
324 * compare two keys in a memcmp fashion
326 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
330 btrfs_disk_key_to_cpu(&k1
, disk
);
332 if (k1
.objectid
> k2
->objectid
)
334 if (k1
.objectid
< k2
->objectid
)
336 if (k1
.type
> k2
->type
)
338 if (k1
.type
< k2
->type
)
340 if (k1
.offset
> k2
->offset
)
342 if (k1
.offset
< k2
->offset
)
348 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
349 struct btrfs_root
*root
, struct extent_buffer
*parent
,
350 int start_slot
, int cache_only
, u64
*last_ret
,
351 struct btrfs_key
*progress
)
353 struct extent_buffer
*cur
;
356 u64 search_start
= *last_ret
;
366 int progress_passed
= 0;
367 struct btrfs_disk_key disk_key
;
369 parent_level
= btrfs_header_level(parent
);
370 if (cache_only
&& parent_level
!= 1)
373 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
374 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
375 root
->fs_info
->running_transaction
->transid
);
378 if (trans
->transid
!= root
->fs_info
->generation
) {
379 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
380 root
->fs_info
->generation
);
384 parent_nritems
= btrfs_header_nritems(parent
);
385 blocksize
= btrfs_level_size(root
, parent_level
- 1);
386 end_slot
= parent_nritems
;
388 if (parent_nritems
== 1)
391 for (i
= start_slot
; i
< end_slot
; i
++) {
394 if (!parent
->map_token
) {
395 map_extent_buffer(parent
,
396 btrfs_node_key_ptr_offset(i
),
397 sizeof(struct btrfs_key_ptr
),
398 &parent
->map_token
, &parent
->kaddr
,
399 &parent
->map_start
, &parent
->map_len
,
402 btrfs_node_key(parent
, &disk_key
, i
);
403 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
407 blocknr
= btrfs_node_blockptr(parent
, i
);
408 gen
= btrfs_node_ptr_generation(parent
, i
);
410 last_block
= blocknr
;
413 other
= btrfs_node_blockptr(parent
, i
- 1);
414 close
= close_blocks(blocknr
, other
, blocksize
);
416 if (!close
&& i
< end_slot
- 2) {
417 other
= btrfs_node_blockptr(parent
, i
+ 1);
418 close
= close_blocks(blocknr
, other
, blocksize
);
421 last_block
= blocknr
;
424 if (parent
->map_token
) {
425 unmap_extent_buffer(parent
, parent
->map_token
,
427 parent
->map_token
= NULL
;
430 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
432 uptodate
= btrfs_buffer_uptodate(cur
, gen
);
435 if (!cur
|| !uptodate
) {
437 free_extent_buffer(cur
);
441 cur
= read_tree_block(root
, blocknr
,
443 } else if (!uptodate
) {
444 btrfs_read_buffer(cur
, gen
);
447 if (search_start
== 0)
448 search_start
= last_block
;
450 btrfs_tree_lock(cur
);
451 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
454 (end_slot
- i
) * blocksize
));
456 btrfs_tree_unlock(cur
);
457 free_extent_buffer(cur
);
460 search_start
= cur
->start
;
461 last_block
= cur
->start
;
462 *last_ret
= search_start
;
463 btrfs_tree_unlock(cur
);
464 free_extent_buffer(cur
);
466 if (parent
->map_token
) {
467 unmap_extent_buffer(parent
, parent
->map_token
,
469 parent
->map_token
= NULL
;
475 * The leaf data grows from end-to-front in the node.
476 * this returns the address of the start of the last item,
477 * which is the stop of the leaf data stack
479 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
480 struct extent_buffer
*leaf
)
482 u32 nr
= btrfs_header_nritems(leaf
);
484 return BTRFS_LEAF_DATA_SIZE(root
);
485 return btrfs_item_offset_nr(leaf
, nr
- 1);
488 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
491 struct extent_buffer
*parent
= NULL
;
492 struct extent_buffer
*node
= path
->nodes
[level
];
493 struct btrfs_disk_key parent_key
;
494 struct btrfs_disk_key node_key
;
497 struct btrfs_key cpukey
;
498 u32 nritems
= btrfs_header_nritems(node
);
500 if (path
->nodes
[level
+ 1])
501 parent
= path
->nodes
[level
+ 1];
503 slot
= path
->slots
[level
];
504 BUG_ON(nritems
== 0);
506 parent_slot
= path
->slots
[level
+ 1];
507 btrfs_node_key(parent
, &parent_key
, parent_slot
);
508 btrfs_node_key(node
, &node_key
, 0);
509 BUG_ON(memcmp(&parent_key
, &node_key
,
510 sizeof(struct btrfs_disk_key
)));
511 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
512 btrfs_header_bytenr(node
));
514 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
516 btrfs_node_key_to_cpu(node
, &cpukey
, slot
- 1);
517 btrfs_node_key(node
, &node_key
, slot
);
518 BUG_ON(comp_keys(&node_key
, &cpukey
) <= 0);
520 if (slot
< nritems
- 1) {
521 btrfs_node_key_to_cpu(node
, &cpukey
, slot
+ 1);
522 btrfs_node_key(node
, &node_key
, slot
);
523 BUG_ON(comp_keys(&node_key
, &cpukey
) >= 0);
528 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
531 struct extent_buffer
*leaf
= path
->nodes
[level
];
532 struct extent_buffer
*parent
= NULL
;
534 struct btrfs_key cpukey
;
535 struct btrfs_disk_key parent_key
;
536 struct btrfs_disk_key leaf_key
;
537 int slot
= path
->slots
[0];
539 u32 nritems
= btrfs_header_nritems(leaf
);
541 if (path
->nodes
[level
+ 1])
542 parent
= path
->nodes
[level
+ 1];
548 parent_slot
= path
->slots
[level
+ 1];
549 btrfs_node_key(parent
, &parent_key
, parent_slot
);
550 btrfs_item_key(leaf
, &leaf_key
, 0);
552 BUG_ON(memcmp(&parent_key
, &leaf_key
,
553 sizeof(struct btrfs_disk_key
)));
554 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
555 btrfs_header_bytenr(leaf
));
558 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
559 btrfs_item_key_to_cpu(leaf
, &cpukey
, i
+ 1);
560 btrfs_item_key(leaf
, &leaf_key
, i
);
561 if (comp_keys(&leaf_key
, &cpukey
) >= 0) {
562 btrfs_print_leaf(root
, leaf
);
563 printk("slot %d offset bad key\n", i
);
566 if (btrfs_item_offset_nr(leaf
, i
) !=
567 btrfs_item_end_nr(leaf
, i
+ 1)) {
568 btrfs_print_leaf(root
, leaf
);
569 printk("slot %d offset bad\n", i
);
573 if (btrfs_item_offset_nr(leaf
, i
) +
574 btrfs_item_size_nr(leaf
, i
) !=
575 BTRFS_LEAF_DATA_SIZE(root
)) {
576 btrfs_print_leaf(root
, leaf
);
577 printk("slot %d first offset bad\n", i
);
583 if (btrfs_item_size_nr(leaf
, nritems
- 1) > 4096) {
584 btrfs_print_leaf(root
, leaf
);
585 printk("slot %d bad size \n", nritems
- 1);
590 if (slot
!= 0 && slot
< nritems
- 1) {
591 btrfs_item_key(leaf
, &leaf_key
, slot
);
592 btrfs_item_key_to_cpu(leaf
, &cpukey
, slot
- 1);
593 if (comp_keys(&leaf_key
, &cpukey
) <= 0) {
594 btrfs_print_leaf(root
, leaf
);
595 printk("slot %d offset bad key\n", slot
);
598 if (btrfs_item_offset_nr(leaf
, slot
- 1) !=
599 btrfs_item_end_nr(leaf
, slot
)) {
600 btrfs_print_leaf(root
, leaf
);
601 printk("slot %d offset bad\n", slot
);
605 if (slot
< nritems
- 1) {
606 btrfs_item_key(leaf
, &leaf_key
, slot
);
607 btrfs_item_key_to_cpu(leaf
, &cpukey
, slot
+ 1);
608 BUG_ON(comp_keys(&leaf_key
, &cpukey
) >= 0);
609 if (btrfs_item_offset_nr(leaf
, slot
) !=
610 btrfs_item_end_nr(leaf
, slot
+ 1)) {
611 btrfs_print_leaf(root
, leaf
);
612 printk("slot %d offset bad\n", slot
);
616 BUG_ON(btrfs_item_offset_nr(leaf
, 0) +
617 btrfs_item_size_nr(leaf
, 0) != BTRFS_LEAF_DATA_SIZE(root
));
621 static int noinline
check_block(struct btrfs_root
*root
,
622 struct btrfs_path
*path
, int level
)
626 if (btrfs_header_level(path
->nodes
[level
]) != level
)
627 printk("warning: bad level %Lu wanted %d found %d\n",
628 path
->nodes
[level
]->start
, level
,
629 btrfs_header_level(path
->nodes
[level
]));
630 found_start
= btrfs_header_bytenr(path
->nodes
[level
]);
631 if (found_start
!= path
->nodes
[level
]->start
) {
632 printk("warning: bad bytentr %Lu found %Lu\n",
633 path
->nodes
[level
]->start
, found_start
);
636 struct extent_buffer
*buf
= path
->nodes
[level
];
638 if (memcmp_extent_buffer(buf
, root
->fs_info
->fsid
,
639 (unsigned long)btrfs_header_fsid(buf
),
641 printk("warning bad block %Lu\n", buf
->start
);
646 return check_leaf(root
, path
, level
);
647 return check_node(root
, path
, level
);
651 * search for key in the extent_buffer. The items start at offset p,
652 * and they are item_size apart. There are 'max' items in p.
654 * the slot in the array is returned via slot, and it points to
655 * the place where you would insert key if it is not found in
658 * slot may point to max if the key is bigger than all of the keys
660 static int generic_bin_search(struct extent_buffer
*eb
, unsigned long p
,
661 int item_size
, struct btrfs_key
*key
,
668 struct btrfs_disk_key
*tmp
= NULL
;
669 struct btrfs_disk_key unaligned
;
670 unsigned long offset
;
671 char *map_token
= NULL
;
673 unsigned long map_start
= 0;
674 unsigned long map_len
= 0;
678 mid
= (low
+ high
) / 2;
679 offset
= p
+ mid
* item_size
;
681 if (!map_token
|| offset
< map_start
||
682 (offset
+ sizeof(struct btrfs_disk_key
)) >
683 map_start
+ map_len
) {
685 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
688 err
= map_extent_buffer(eb
, offset
,
689 sizeof(struct btrfs_disk_key
),
691 &map_start
, &map_len
, KM_USER0
);
694 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
697 read_extent_buffer(eb
, &unaligned
,
698 offset
, sizeof(unaligned
));
703 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
706 ret
= comp_keys(tmp
, key
);
715 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
721 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
726 * simple bin_search frontend that does the right thing for
729 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
730 int level
, int *slot
)
733 return generic_bin_search(eb
,
734 offsetof(struct btrfs_leaf
, items
),
735 sizeof(struct btrfs_item
),
736 key
, btrfs_header_nritems(eb
),
739 return generic_bin_search(eb
,
740 offsetof(struct btrfs_node
, ptrs
),
741 sizeof(struct btrfs_key_ptr
),
742 key
, btrfs_header_nritems(eb
),
748 static struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
749 struct extent_buffer
*parent
, int slot
)
751 int level
= btrfs_header_level(parent
);
754 if (slot
>= btrfs_header_nritems(parent
))
759 return read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
760 btrfs_level_size(root
, level
- 1),
761 btrfs_node_ptr_generation(parent
, slot
));
764 static int balance_level(struct btrfs_trans_handle
*trans
,
765 struct btrfs_root
*root
,
766 struct btrfs_path
*path
, int level
)
768 struct extent_buffer
*right
= NULL
;
769 struct extent_buffer
*mid
;
770 struct extent_buffer
*left
= NULL
;
771 struct extent_buffer
*parent
= NULL
;
775 int orig_slot
= path
->slots
[level
];
776 int err_on_enospc
= 0;
782 mid
= path
->nodes
[level
];
783 WARN_ON(!path
->locks
[level
]);
784 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
786 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
788 if (level
< BTRFS_MAX_LEVEL
- 1)
789 parent
= path
->nodes
[level
+ 1];
790 pslot
= path
->slots
[level
+ 1];
793 * deal with the case where there is only one pointer in the root
794 * by promoting the node below to a root
797 struct extent_buffer
*child
;
799 if (btrfs_header_nritems(mid
) != 1)
802 /* promote the child to a root */
803 child
= read_node_slot(root
, mid
, 0);
804 btrfs_tree_lock(child
);
806 ret
= btrfs_cow_block(trans
, root
, child
, mid
, 0, &child
);
809 spin_lock(&root
->node_lock
);
811 spin_unlock(&root
->node_lock
);
813 add_root_to_dirty_list(root
);
814 btrfs_tree_unlock(child
);
815 path
->locks
[level
] = 0;
816 path
->nodes
[level
] = NULL
;
817 clean_tree_block(trans
, root
, mid
);
818 btrfs_tree_unlock(mid
);
819 /* once for the path */
820 free_extent_buffer(mid
);
821 ret
= btrfs_free_extent(trans
, root
, mid
->start
, mid
->len
,
822 root
->root_key
.objectid
,
823 btrfs_header_generation(mid
), 0, 0, 1);
824 /* once for the root ptr */
825 free_extent_buffer(mid
);
828 if (btrfs_header_nritems(mid
) >
829 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
832 if (btrfs_header_nritems(mid
) < 2)
835 left
= read_node_slot(root
, parent
, pslot
- 1);
837 btrfs_tree_lock(left
);
838 wret
= btrfs_cow_block(trans
, root
, left
,
839 parent
, pslot
- 1, &left
);
845 right
= read_node_slot(root
, parent
, pslot
+ 1);
847 btrfs_tree_lock(right
);
848 wret
= btrfs_cow_block(trans
, root
, right
,
849 parent
, pslot
+ 1, &right
);
856 /* first, try to make some room in the middle buffer */
858 orig_slot
+= btrfs_header_nritems(left
);
859 wret
= push_node_left(trans
, root
, left
, mid
, 1);
862 if (btrfs_header_nritems(mid
) < 2)
867 * then try to empty the right most buffer into the middle
870 wret
= push_node_left(trans
, root
, mid
, right
, 1);
871 if (wret
< 0 && wret
!= -ENOSPC
)
873 if (btrfs_header_nritems(right
) == 0) {
874 u64 bytenr
= right
->start
;
875 u64 generation
= btrfs_header_generation(parent
);
876 u32 blocksize
= right
->len
;
878 clean_tree_block(trans
, root
, right
);
879 btrfs_tree_unlock(right
);
880 free_extent_buffer(right
);
882 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
886 wret
= btrfs_free_extent(trans
, root
, bytenr
,
888 btrfs_header_owner(parent
),
889 generation
, 0, 0, 1);
893 struct btrfs_disk_key right_key
;
894 btrfs_node_key(right
, &right_key
, 0);
895 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
896 btrfs_mark_buffer_dirty(parent
);
899 if (btrfs_header_nritems(mid
) == 1) {
901 * we're not allowed to leave a node with one item in the
902 * tree during a delete. A deletion from lower in the tree
903 * could try to delete the only pointer in this node.
904 * So, pull some keys from the left.
905 * There has to be a left pointer at this point because
906 * otherwise we would have pulled some pointers from the
910 wret
= balance_node_right(trans
, root
, mid
, left
);
916 wret
= push_node_left(trans
, root
, left
, mid
, 1);
922 if (btrfs_header_nritems(mid
) == 0) {
923 /* we've managed to empty the middle node, drop it */
924 u64 root_gen
= btrfs_header_generation(parent
);
925 u64 bytenr
= mid
->start
;
926 u32 blocksize
= mid
->len
;
928 clean_tree_block(trans
, root
, mid
);
929 btrfs_tree_unlock(mid
);
930 free_extent_buffer(mid
);
932 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
935 wret
= btrfs_free_extent(trans
, root
, bytenr
, blocksize
,
936 btrfs_header_owner(parent
),
941 /* update the parent key to reflect our changes */
942 struct btrfs_disk_key mid_key
;
943 btrfs_node_key(mid
, &mid_key
, 0);
944 btrfs_set_node_key(parent
, &mid_key
, pslot
);
945 btrfs_mark_buffer_dirty(parent
);
948 /* update the path */
950 if (btrfs_header_nritems(left
) > orig_slot
) {
951 extent_buffer_get(left
);
952 /* left was locked after cow */
953 path
->nodes
[level
] = left
;
954 path
->slots
[level
+ 1] -= 1;
955 path
->slots
[level
] = orig_slot
;
957 btrfs_tree_unlock(mid
);
958 free_extent_buffer(mid
);
961 orig_slot
-= btrfs_header_nritems(left
);
962 path
->slots
[level
] = orig_slot
;
965 /* double check we haven't messed things up */
966 check_block(root
, path
, level
);
968 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
972 btrfs_tree_unlock(right
);
973 free_extent_buffer(right
);
976 if (path
->nodes
[level
] != left
)
977 btrfs_tree_unlock(left
);
978 free_extent_buffer(left
);
983 /* returns zero if the push worked, non-zero otherwise */
984 static int noinline
push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
985 struct btrfs_root
*root
,
986 struct btrfs_path
*path
, int level
)
988 struct extent_buffer
*right
= NULL
;
989 struct extent_buffer
*mid
;
990 struct extent_buffer
*left
= NULL
;
991 struct extent_buffer
*parent
= NULL
;
995 int orig_slot
= path
->slots
[level
];
1001 mid
= path
->nodes
[level
];
1002 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1003 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
1005 if (level
< BTRFS_MAX_LEVEL
- 1)
1006 parent
= path
->nodes
[level
+ 1];
1007 pslot
= path
->slots
[level
+ 1];
1012 left
= read_node_slot(root
, parent
, pslot
- 1);
1014 /* first, try to make some room in the middle buffer */
1018 btrfs_tree_lock(left
);
1019 left_nr
= btrfs_header_nritems(left
);
1020 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1023 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
1028 wret
= push_node_left(trans
, root
,
1035 struct btrfs_disk_key disk_key
;
1036 orig_slot
+= left_nr
;
1037 btrfs_node_key(mid
, &disk_key
, 0);
1038 btrfs_set_node_key(parent
, &disk_key
, pslot
);
1039 btrfs_mark_buffer_dirty(parent
);
1040 if (btrfs_header_nritems(left
) > orig_slot
) {
1041 path
->nodes
[level
] = left
;
1042 path
->slots
[level
+ 1] -= 1;
1043 path
->slots
[level
] = orig_slot
;
1044 btrfs_tree_unlock(mid
);
1045 free_extent_buffer(mid
);
1048 btrfs_header_nritems(left
);
1049 path
->slots
[level
] = orig_slot
;
1050 btrfs_tree_unlock(left
);
1051 free_extent_buffer(left
);
1055 btrfs_tree_unlock(left
);
1056 free_extent_buffer(left
);
1058 right
= read_node_slot(root
, parent
, pslot
+ 1);
1061 * then try to empty the right most buffer into the middle
1065 btrfs_tree_lock(right
);
1066 right_nr
= btrfs_header_nritems(right
);
1067 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1070 ret
= btrfs_cow_block(trans
, root
, right
,
1076 wret
= balance_node_right(trans
, root
,
1083 struct btrfs_disk_key disk_key
;
1085 btrfs_node_key(right
, &disk_key
, 0);
1086 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
1087 btrfs_mark_buffer_dirty(parent
);
1089 if (btrfs_header_nritems(mid
) <= orig_slot
) {
1090 path
->nodes
[level
] = right
;
1091 path
->slots
[level
+ 1] += 1;
1092 path
->slots
[level
] = orig_slot
-
1093 btrfs_header_nritems(mid
);
1094 btrfs_tree_unlock(mid
);
1095 free_extent_buffer(mid
);
1097 btrfs_tree_unlock(right
);
1098 free_extent_buffer(right
);
1102 btrfs_tree_unlock(right
);
1103 free_extent_buffer(right
);
1109 * readahead one full node of leaves
1111 static void reada_for_search(struct btrfs_root
*root
, struct btrfs_path
*path
,
1112 int level
, int slot
, u64 objectid
)
1114 struct extent_buffer
*node
;
1115 struct btrfs_disk_key disk_key
;
1121 int direction
= path
->reada
;
1122 struct extent_buffer
*eb
;
1130 if (!path
->nodes
[level
])
1133 node
= path
->nodes
[level
];
1135 search
= btrfs_node_blockptr(node
, slot
);
1136 blocksize
= btrfs_level_size(root
, level
- 1);
1137 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
1139 free_extent_buffer(eb
);
1143 highest_read
= search
;
1144 lowest_read
= search
;
1146 nritems
= btrfs_header_nritems(node
);
1149 if (direction
< 0) {
1153 } else if (direction
> 0) {
1158 if (path
->reada
< 0 && objectid
) {
1159 btrfs_node_key(node
, &disk_key
, nr
);
1160 if (btrfs_disk_key_objectid(&disk_key
) != objectid
)
1163 search
= btrfs_node_blockptr(node
, nr
);
1164 if ((search
>= lowest_read
&& search
<= highest_read
) ||
1165 (search
< lowest_read
&& lowest_read
- search
<= 32768) ||
1166 (search
> highest_read
&& search
- highest_read
<= 32768)) {
1167 readahead_tree_block(root
, search
, blocksize
,
1168 btrfs_node_ptr_generation(node
, nr
));
1172 if (path
->reada
< 2 && (nread
> (256 * 1024) || nscan
> 32))
1174 if(nread
> (1024 * 1024) || nscan
> 128)
1177 if (search
< lowest_read
)
1178 lowest_read
= search
;
1179 if (search
> highest_read
)
1180 highest_read
= search
;
1184 static void unlock_up(struct btrfs_path
*path
, int level
, int lowest_unlock
)
1187 int skip_level
= level
;
1189 struct extent_buffer
*t
;
1191 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1192 if (!path
->nodes
[i
])
1194 if (!path
->locks
[i
])
1196 if (!no_skips
&& path
->slots
[i
] == 0) {
1200 if (!no_skips
&& path
->keep_locks
) {
1203 nritems
= btrfs_header_nritems(t
);
1204 if (nritems
< 1 || path
->slots
[i
] >= nritems
- 1) {
1209 if (skip_level
< i
&& i
>= lowest_unlock
)
1213 if (i
>= lowest_unlock
&& i
> skip_level
&& path
->locks
[i
]) {
1214 btrfs_tree_unlock(t
);
1221 * look for key in the tree. path is filled in with nodes along the way
1222 * if key is found, we return zero and you can find the item in the leaf
1223 * level of the path (level 0)
1225 * If the key isn't found, the path points to the slot where it should
1226 * be inserted, and 1 is returned. If there are other errors during the
1227 * search a negative error number is returned.
1229 * if ins_len > 0, nodes and leaves will be split as we walk down the
1230 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1233 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
1234 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
1237 struct extent_buffer
*b
;
1238 struct extent_buffer
*tmp
;
1242 int should_reada
= p
->reada
;
1243 int lowest_unlock
= 1;
1245 u8 lowest_level
= 0;
1249 lowest_level
= p
->lowest_level
;
1250 WARN_ON(lowest_level
&& ins_len
);
1251 WARN_ON(p
->nodes
[0] != NULL
);
1252 WARN_ON(cow
&& root
== root
->fs_info
->extent_root
&&
1253 !mutex_is_locked(&root
->fs_info
->alloc_mutex
));
1254 WARN_ON(root
== root
->fs_info
->chunk_root
&&
1255 !mutex_is_locked(&root
->fs_info
->chunk_mutex
));
1256 WARN_ON(root
== root
->fs_info
->dev_root
&&
1257 !mutex_is_locked(&root
->fs_info
->chunk_mutex
));
1261 if (p
->skip_locking
)
1262 b
= btrfs_root_node(root
);
1264 b
= btrfs_lock_root_node(root
);
1267 level
= btrfs_header_level(b
);
1270 wret
= btrfs_cow_block(trans
, root
, b
,
1271 p
->nodes
[level
+ 1],
1272 p
->slots
[level
+ 1],
1275 free_extent_buffer(b
);
1279 BUG_ON(!cow
&& ins_len
);
1280 if (level
!= btrfs_header_level(b
))
1282 level
= btrfs_header_level(b
);
1283 p
->nodes
[level
] = b
;
1284 if (!p
->skip_locking
)
1285 p
->locks
[level
] = 1;
1286 ret
= check_block(root
, p
, level
);
1290 ret
= bin_search(b
, key
, level
, &slot
);
1292 if (ret
&& slot
> 0)
1294 p
->slots
[level
] = slot
;
1295 if (ins_len
> 0 && btrfs_header_nritems(b
) >=
1296 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3) {
1297 int sret
= split_node(trans
, root
, p
, level
);
1301 b
= p
->nodes
[level
];
1302 slot
= p
->slots
[level
];
1303 } else if (ins_len
< 0) {
1304 int sret
= balance_level(trans
, root
, p
,
1308 b
= p
->nodes
[level
];
1310 btrfs_release_path(NULL
, p
);
1313 slot
= p
->slots
[level
];
1314 BUG_ON(btrfs_header_nritems(b
) == 1);
1316 unlock_up(p
, level
, lowest_unlock
);
1318 /* this is only true while dropping a snapshot */
1319 if (level
== lowest_level
) {
1323 blocknr
= btrfs_node_blockptr(b
, slot
);
1324 gen
= btrfs_node_ptr_generation(b
, slot
);
1325 blocksize
= btrfs_level_size(root
, level
- 1);
1327 tmp
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
1328 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
1332 * reduce lock contention at high levels
1333 * of the btree by dropping locks before
1337 btrfs_release_path(NULL
, p
);
1339 free_extent_buffer(tmp
);
1341 reada_for_search(root
, p
,
1345 tmp
= read_tree_block(root
, blocknr
,
1348 free_extent_buffer(tmp
);
1352 free_extent_buffer(tmp
);
1354 reada_for_search(root
, p
,
1357 b
= read_node_slot(root
, b
, slot
);
1360 if (!p
->skip_locking
)
1363 p
->slots
[level
] = slot
;
1364 if (ins_len
> 0 && btrfs_leaf_free_space(root
, b
) <
1365 sizeof(struct btrfs_item
) + ins_len
) {
1366 int sret
= split_leaf(trans
, root
, key
,
1367 p
, ins_len
, ret
== 0);
1372 unlock_up(p
, level
, lowest_unlock
);
1380 * adjust the pointers going up the tree, starting at level
1381 * making sure the right key of each node is points to 'key'.
1382 * This is used after shifting pointers to the left, so it stops
1383 * fixing up pointers when a given leaf/node is not in slot 0 of the
1386 * If this fails to write a tree block, it returns -1, but continues
1387 * fixing up the blocks in ram so the tree is consistent.
1389 static int fixup_low_keys(struct btrfs_trans_handle
*trans
,
1390 struct btrfs_root
*root
, struct btrfs_path
*path
,
1391 struct btrfs_disk_key
*key
, int level
)
1395 struct extent_buffer
*t
;
1397 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1398 int tslot
= path
->slots
[i
];
1399 if (!path
->nodes
[i
])
1402 btrfs_set_node_key(t
, key
, tslot
);
1403 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
1411 * try to push data from one node into the next node left in the
1414 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1415 * error, and > 0 if there was no room in the left hand block.
1417 static int push_node_left(struct btrfs_trans_handle
*trans
,
1418 struct btrfs_root
*root
, struct extent_buffer
*dst
,
1419 struct extent_buffer
*src
, int empty
)
1426 src_nritems
= btrfs_header_nritems(src
);
1427 dst_nritems
= btrfs_header_nritems(dst
);
1428 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1429 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1430 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1432 if (!empty
&& src_nritems
<= 8)
1435 if (push_items
<= 0) {
1440 push_items
= min(src_nritems
, push_items
);
1441 if (push_items
< src_nritems
) {
1442 /* leave at least 8 pointers in the node if
1443 * we aren't going to empty it
1445 if (src_nritems
- push_items
< 8) {
1446 if (push_items
<= 8)
1452 push_items
= min(src_nritems
- 8, push_items
);
1454 copy_extent_buffer(dst
, src
,
1455 btrfs_node_key_ptr_offset(dst_nritems
),
1456 btrfs_node_key_ptr_offset(0),
1457 push_items
* sizeof(struct btrfs_key_ptr
));
1459 if (push_items
< src_nritems
) {
1460 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
1461 btrfs_node_key_ptr_offset(push_items
),
1462 (src_nritems
- push_items
) *
1463 sizeof(struct btrfs_key_ptr
));
1465 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1466 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1467 btrfs_mark_buffer_dirty(src
);
1468 btrfs_mark_buffer_dirty(dst
);
1473 * try to push data from one node into the next node right in the
1476 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1477 * error, and > 0 if there was no room in the right hand block.
1479 * this will only push up to 1/2 the contents of the left node over
1481 static int balance_node_right(struct btrfs_trans_handle
*trans
,
1482 struct btrfs_root
*root
,
1483 struct extent_buffer
*dst
,
1484 struct extent_buffer
*src
)
1492 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1493 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1495 src_nritems
= btrfs_header_nritems(src
);
1496 dst_nritems
= btrfs_header_nritems(dst
);
1497 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1498 if (push_items
<= 0) {
1502 if (src_nritems
< 4) {
1506 max_push
= src_nritems
/ 2 + 1;
1507 /* don't try to empty the node */
1508 if (max_push
>= src_nritems
) {
1512 if (max_push
< push_items
)
1513 push_items
= max_push
;
1515 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
1516 btrfs_node_key_ptr_offset(0),
1518 sizeof(struct btrfs_key_ptr
));
1520 copy_extent_buffer(dst
, src
,
1521 btrfs_node_key_ptr_offset(0),
1522 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
1523 push_items
* sizeof(struct btrfs_key_ptr
));
1525 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1526 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1528 btrfs_mark_buffer_dirty(src
);
1529 btrfs_mark_buffer_dirty(dst
);
1534 * helper function to insert a new root level in the tree.
1535 * A new node is allocated, and a single item is inserted to
1536 * point to the existing root
1538 * returns zero on success or < 0 on failure.
1540 static int noinline
insert_new_root(struct btrfs_trans_handle
*trans
,
1541 struct btrfs_root
*root
,
1542 struct btrfs_path
*path
, int level
)
1546 struct extent_buffer
*lower
;
1547 struct extent_buffer
*c
;
1548 struct extent_buffer
*old
;
1549 struct btrfs_disk_key lower_key
;
1551 BUG_ON(path
->nodes
[level
]);
1552 BUG_ON(path
->nodes
[level
-1] != root
->node
);
1555 root_gen
= trans
->transid
;
1559 lower
= path
->nodes
[level
-1];
1561 btrfs_item_key(lower
, &lower_key
, 0);
1563 btrfs_node_key(lower
, &lower_key
, 0);
1565 c
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
,
1566 root
->root_key
.objectid
,
1567 root_gen
, lower_key
.objectid
, level
,
1568 root
->node
->start
, 0);
1572 memset_extent_buffer(c
, 0, 0, root
->nodesize
);
1573 btrfs_set_header_nritems(c
, 1);
1574 btrfs_set_header_level(c
, level
);
1575 btrfs_set_header_bytenr(c
, c
->start
);
1576 btrfs_set_header_generation(c
, trans
->transid
);
1577 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
1579 write_extent_buffer(c
, root
->fs_info
->fsid
,
1580 (unsigned long)btrfs_header_fsid(c
),
1583 write_extent_buffer(c
, root
->fs_info
->chunk_tree_uuid
,
1584 (unsigned long)btrfs_header_chunk_tree_uuid(c
),
1587 btrfs_set_node_key(c
, &lower_key
, 0);
1588 btrfs_set_node_blockptr(c
, 0, lower
->start
);
1589 lower_gen
= btrfs_header_generation(lower
);
1590 WARN_ON(lower_gen
== 0);
1592 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
1594 btrfs_mark_buffer_dirty(c
);
1596 spin_lock(&root
->node_lock
);
1599 spin_unlock(&root
->node_lock
);
1601 /* the super has an extra ref to root->node */
1602 free_extent_buffer(old
);
1604 add_root_to_dirty_list(root
);
1605 extent_buffer_get(c
);
1606 path
->nodes
[level
] = c
;
1607 path
->locks
[level
] = 1;
1608 path
->slots
[level
] = 0;
1610 if (root
->ref_cows
&& lower_gen
!= trans
->transid
) {
1611 struct btrfs_path
*back_path
= btrfs_alloc_path();
1613 mutex_lock(&root
->fs_info
->alloc_mutex
);
1614 ret
= btrfs_insert_extent_backref(trans
,
1615 root
->fs_info
->extent_root
,
1617 root
->root_key
.objectid
,
1618 trans
->transid
, 0, 0);
1620 mutex_unlock(&root
->fs_info
->alloc_mutex
);
1621 btrfs_free_path(back_path
);
1627 * worker function to insert a single pointer in a node.
1628 * the node should have enough room for the pointer already
1630 * slot and level indicate where you want the key to go, and
1631 * blocknr is the block the key points to.
1633 * returns zero on success and < 0 on any error
1635 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
1636 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
1637 *key
, u64 bytenr
, int slot
, int level
)
1639 struct extent_buffer
*lower
;
1642 BUG_ON(!path
->nodes
[level
]);
1643 lower
= path
->nodes
[level
];
1644 nritems
= btrfs_header_nritems(lower
);
1647 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
1649 if (slot
!= nritems
) {
1650 memmove_extent_buffer(lower
,
1651 btrfs_node_key_ptr_offset(slot
+ 1),
1652 btrfs_node_key_ptr_offset(slot
),
1653 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
1655 btrfs_set_node_key(lower
, key
, slot
);
1656 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
1657 WARN_ON(trans
->transid
== 0);
1658 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
1659 btrfs_set_header_nritems(lower
, nritems
+ 1);
1660 btrfs_mark_buffer_dirty(lower
);
1665 * split the node at the specified level in path in two.
1666 * The path is corrected to point to the appropriate node after the split
1668 * Before splitting this tries to make some room in the node by pushing
1669 * left and right, if either one works, it returns right away.
1671 * returns 0 on success and < 0 on failure
1673 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
1674 *root
, struct btrfs_path
*path
, int level
)
1677 struct extent_buffer
*c
;
1678 struct extent_buffer
*split
;
1679 struct btrfs_disk_key disk_key
;
1685 c
= path
->nodes
[level
];
1686 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
1687 if (c
== root
->node
) {
1688 /* trying to split the root, lets make a new one */
1689 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
1693 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
1694 c
= path
->nodes
[level
];
1695 if (!ret
&& btrfs_header_nritems(c
) <
1696 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3)
1702 c_nritems
= btrfs_header_nritems(c
);
1704 root_gen
= trans
->transid
;
1708 btrfs_node_key(c
, &disk_key
, 0);
1709 split
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
,
1710 root
->root_key
.objectid
,
1712 btrfs_disk_key_objectid(&disk_key
),
1713 level
, c
->start
, 0);
1715 return PTR_ERR(split
);
1717 btrfs_set_header_flags(split
, btrfs_header_flags(c
));
1718 btrfs_set_header_level(split
, btrfs_header_level(c
));
1719 btrfs_set_header_bytenr(split
, split
->start
);
1720 btrfs_set_header_generation(split
, trans
->transid
);
1721 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
1722 btrfs_set_header_flags(split
, 0);
1723 write_extent_buffer(split
, root
->fs_info
->fsid
,
1724 (unsigned long)btrfs_header_fsid(split
),
1726 write_extent_buffer(split
, root
->fs_info
->chunk_tree_uuid
,
1727 (unsigned long)btrfs_header_chunk_tree_uuid(split
),
1730 mid
= (c_nritems
+ 1) / 2;
1732 copy_extent_buffer(split
, c
,
1733 btrfs_node_key_ptr_offset(0),
1734 btrfs_node_key_ptr_offset(mid
),
1735 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
1736 btrfs_set_header_nritems(split
, c_nritems
- mid
);
1737 btrfs_set_header_nritems(c
, mid
);
1740 btrfs_mark_buffer_dirty(c
);
1741 btrfs_mark_buffer_dirty(split
);
1743 btrfs_node_key(split
, &disk_key
, 0);
1744 wret
= insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
1745 path
->slots
[level
+ 1] + 1,
1750 if (path
->slots
[level
] >= mid
) {
1751 path
->slots
[level
] -= mid
;
1752 btrfs_tree_unlock(c
);
1753 free_extent_buffer(c
);
1754 path
->nodes
[level
] = split
;
1755 path
->slots
[level
+ 1] += 1;
1757 btrfs_tree_unlock(split
);
1758 free_extent_buffer(split
);
1764 * how many bytes are required to store the items in a leaf. start
1765 * and nr indicate which items in the leaf to check. This totals up the
1766 * space used both by the item structs and the item data
1768 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
1771 int nritems
= btrfs_header_nritems(l
);
1772 int end
= min(nritems
, start
+ nr
) - 1;
1776 data_len
= btrfs_item_end_nr(l
, start
);
1777 data_len
= data_len
- btrfs_item_offset_nr(l
, end
);
1778 data_len
+= sizeof(struct btrfs_item
) * nr
;
1779 WARN_ON(data_len
< 0);
1784 * The space between the end of the leaf items and
1785 * the start of the leaf data. IOW, how much room
1786 * the leaf has left for both items and data
1788 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct extent_buffer
*leaf
)
1790 int nritems
= btrfs_header_nritems(leaf
);
1792 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
1794 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1795 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
1796 leaf_space_used(leaf
, 0, nritems
), nritems
);
1802 * push some data in the path leaf to the right, trying to free up at
1803 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1805 * returns 1 if the push failed because the other node didn't have enough
1806 * room, 0 if everything worked out and < 0 if there were major errors.
1808 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
1809 *root
, struct btrfs_path
*path
, int data_size
,
1812 struct extent_buffer
*left
= path
->nodes
[0];
1813 struct extent_buffer
*right
;
1814 struct extent_buffer
*upper
;
1815 struct btrfs_disk_key disk_key
;
1821 struct btrfs_item
*item
;
1829 slot
= path
->slots
[1];
1830 if (!path
->nodes
[1]) {
1833 upper
= path
->nodes
[1];
1834 if (slot
>= btrfs_header_nritems(upper
) - 1)
1837 WARN_ON(!btrfs_tree_locked(path
->nodes
[1]));
1839 right
= read_node_slot(root
, upper
, slot
+ 1);
1840 btrfs_tree_lock(right
);
1841 free_space
= btrfs_leaf_free_space(root
, right
);
1842 if (free_space
< data_size
+ sizeof(struct btrfs_item
))
1845 /* cow and double check */
1846 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
1851 free_space
= btrfs_leaf_free_space(root
, right
);
1852 if (free_space
< data_size
+ sizeof(struct btrfs_item
))
1855 left_nritems
= btrfs_header_nritems(left
);
1856 if (left_nritems
== 0)
1864 i
= left_nritems
- 1;
1866 item
= btrfs_item_nr(left
, i
);
1868 if (path
->slots
[0] == i
)
1869 push_space
+= data_size
+ sizeof(*item
);
1871 if (!left
->map_token
) {
1872 map_extent_buffer(left
, (unsigned long)item
,
1873 sizeof(struct btrfs_item
),
1874 &left
->map_token
, &left
->kaddr
,
1875 &left
->map_start
, &left
->map_len
,
1879 this_item_size
= btrfs_item_size(left
, item
);
1880 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
1883 push_space
+= this_item_size
+ sizeof(*item
);
1888 if (left
->map_token
) {
1889 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
1890 left
->map_token
= NULL
;
1893 if (push_items
== 0)
1896 if (!empty
&& push_items
== left_nritems
)
1899 /* push left to right */
1900 right_nritems
= btrfs_header_nritems(right
);
1902 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
1903 push_space
-= leaf_data_end(root
, left
);
1905 /* make room in the right data area */
1906 data_end
= leaf_data_end(root
, right
);
1907 memmove_extent_buffer(right
,
1908 btrfs_leaf_data(right
) + data_end
- push_space
,
1909 btrfs_leaf_data(right
) + data_end
,
1910 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
1912 /* copy from the left data area */
1913 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
1914 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1915 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1918 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
1919 btrfs_item_nr_offset(0),
1920 right_nritems
* sizeof(struct btrfs_item
));
1922 /* copy the items from left to right */
1923 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
1924 btrfs_item_nr_offset(left_nritems
- push_items
),
1925 push_items
* sizeof(struct btrfs_item
));
1927 /* update the item pointers */
1928 right_nritems
+= push_items
;
1929 btrfs_set_header_nritems(right
, right_nritems
);
1930 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1931 for (i
= 0; i
< right_nritems
; i
++) {
1932 item
= btrfs_item_nr(right
, i
);
1933 if (!right
->map_token
) {
1934 map_extent_buffer(right
, (unsigned long)item
,
1935 sizeof(struct btrfs_item
),
1936 &right
->map_token
, &right
->kaddr
,
1937 &right
->map_start
, &right
->map_len
,
1940 push_space
-= btrfs_item_size(right
, item
);
1941 btrfs_set_item_offset(right
, item
, push_space
);
1944 if (right
->map_token
) {
1945 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
1946 right
->map_token
= NULL
;
1948 left_nritems
-= push_items
;
1949 btrfs_set_header_nritems(left
, left_nritems
);
1952 btrfs_mark_buffer_dirty(left
);
1953 btrfs_mark_buffer_dirty(right
);
1955 btrfs_item_key(right
, &disk_key
, 0);
1956 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
1957 btrfs_mark_buffer_dirty(upper
);
1959 /* then fixup the leaf pointer in the path */
1960 if (path
->slots
[0] >= left_nritems
) {
1961 path
->slots
[0] -= left_nritems
;
1962 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
1963 clean_tree_block(trans
, root
, path
->nodes
[0]);
1964 btrfs_tree_unlock(path
->nodes
[0]);
1965 free_extent_buffer(path
->nodes
[0]);
1966 path
->nodes
[0] = right
;
1967 path
->slots
[1] += 1;
1969 btrfs_tree_unlock(right
);
1970 free_extent_buffer(right
);
1975 btrfs_tree_unlock(right
);
1976 free_extent_buffer(right
);
1981 * push some data in the path leaf to the left, trying to free up at
1982 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1984 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1985 *root
, struct btrfs_path
*path
, int data_size
,
1988 struct btrfs_disk_key disk_key
;
1989 struct extent_buffer
*right
= path
->nodes
[0];
1990 struct extent_buffer
*left
;
1996 struct btrfs_item
*item
;
1997 u32 old_left_nritems
;
2003 u32 old_left_item_size
;
2005 slot
= path
->slots
[1];
2008 if (!path
->nodes
[1])
2011 right_nritems
= btrfs_header_nritems(right
);
2012 if (right_nritems
== 0) {
2016 WARN_ON(!btrfs_tree_locked(path
->nodes
[1]));
2018 left
= read_node_slot(root
, path
->nodes
[1], slot
- 1);
2019 btrfs_tree_lock(left
);
2020 free_space
= btrfs_leaf_free_space(root
, left
);
2021 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
2026 /* cow and double check */
2027 ret
= btrfs_cow_block(trans
, root
, left
,
2028 path
->nodes
[1], slot
- 1, &left
);
2030 /* we hit -ENOSPC, but it isn't fatal here */
2035 free_space
= btrfs_leaf_free_space(root
, left
);
2036 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
2044 nr
= right_nritems
- 1;
2046 for (i
= 0; i
< nr
; i
++) {
2047 item
= btrfs_item_nr(right
, i
);
2048 if (!right
->map_token
) {
2049 map_extent_buffer(right
, (unsigned long)item
,
2050 sizeof(struct btrfs_item
),
2051 &right
->map_token
, &right
->kaddr
,
2052 &right
->map_start
, &right
->map_len
,
2056 if (path
->slots
[0] == i
)
2057 push_space
+= data_size
+ sizeof(*item
);
2059 this_item_size
= btrfs_item_size(right
, item
);
2060 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
2064 push_space
+= this_item_size
+ sizeof(*item
);
2067 if (right
->map_token
) {
2068 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2069 right
->map_token
= NULL
;
2072 if (push_items
== 0) {
2076 if (!empty
&& push_items
== btrfs_header_nritems(right
))
2079 /* push data from right to left */
2080 copy_extent_buffer(left
, right
,
2081 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
2082 btrfs_item_nr_offset(0),
2083 push_items
* sizeof(struct btrfs_item
));
2085 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
2086 btrfs_item_offset_nr(right
, push_items
-1);
2088 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
2089 leaf_data_end(root
, left
) - push_space
,
2090 btrfs_leaf_data(right
) +
2091 btrfs_item_offset_nr(right
, push_items
- 1),
2093 old_left_nritems
= btrfs_header_nritems(left
);
2094 BUG_ON(old_left_nritems
< 0);
2096 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
2097 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
2100 item
= btrfs_item_nr(left
, i
);
2101 if (!left
->map_token
) {
2102 map_extent_buffer(left
, (unsigned long)item
,
2103 sizeof(struct btrfs_item
),
2104 &left
->map_token
, &left
->kaddr
,
2105 &left
->map_start
, &left
->map_len
,
2109 ioff
= btrfs_item_offset(left
, item
);
2110 btrfs_set_item_offset(left
, item
,
2111 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
));
2113 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
2114 if (left
->map_token
) {
2115 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
2116 left
->map_token
= NULL
;
2119 /* fixup right node */
2120 if (push_items
> right_nritems
) {
2121 printk("push items %d nr %u\n", push_items
, right_nritems
);
2125 if (push_items
< right_nritems
) {
2126 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
2127 leaf_data_end(root
, right
);
2128 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
2129 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
2130 btrfs_leaf_data(right
) +
2131 leaf_data_end(root
, right
), push_space
);
2133 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
2134 btrfs_item_nr_offset(push_items
),
2135 (btrfs_header_nritems(right
) - push_items
) *
2136 sizeof(struct btrfs_item
));
2138 right_nritems
-= push_items
;
2139 btrfs_set_header_nritems(right
, right_nritems
);
2140 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
2141 for (i
= 0; i
< right_nritems
; i
++) {
2142 item
= btrfs_item_nr(right
, i
);
2144 if (!right
->map_token
) {
2145 map_extent_buffer(right
, (unsigned long)item
,
2146 sizeof(struct btrfs_item
),
2147 &right
->map_token
, &right
->kaddr
,
2148 &right
->map_start
, &right
->map_len
,
2152 push_space
= push_space
- btrfs_item_size(right
, item
);
2153 btrfs_set_item_offset(right
, item
, push_space
);
2155 if (right
->map_token
) {
2156 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2157 right
->map_token
= NULL
;
2160 btrfs_mark_buffer_dirty(left
);
2162 btrfs_mark_buffer_dirty(right
);
2164 btrfs_item_key(right
, &disk_key
, 0);
2165 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2169 /* then fixup the leaf pointer in the path */
2170 if (path
->slots
[0] < push_items
) {
2171 path
->slots
[0] += old_left_nritems
;
2172 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
2173 clean_tree_block(trans
, root
, path
->nodes
[0]);
2174 btrfs_tree_unlock(path
->nodes
[0]);
2175 free_extent_buffer(path
->nodes
[0]);
2176 path
->nodes
[0] = left
;
2177 path
->slots
[1] -= 1;
2179 btrfs_tree_unlock(left
);
2180 free_extent_buffer(left
);
2181 path
->slots
[0] -= push_items
;
2183 BUG_ON(path
->slots
[0] < 0);
2186 btrfs_tree_unlock(left
);
2187 free_extent_buffer(left
);
2192 * split the path's leaf in two, making sure there is at least data_size
2193 * available for the resulting leaf level of the path.
2195 * returns 0 if all went well and < 0 on failure.
2197 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
2198 *root
, struct btrfs_key
*ins_key
,
2199 struct btrfs_path
*path
, int data_size
, int extend
)
2202 struct extent_buffer
*l
;
2206 struct extent_buffer
*right
;
2207 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
2214 int num_doubles
= 0;
2215 struct btrfs_disk_key disk_key
;
2218 space_needed
= data_size
;
2221 root_gen
= trans
->transid
;
2225 /* first try to make some room by pushing left and right */
2226 if (ins_key
->type
!= BTRFS_DIR_ITEM_KEY
) {
2227 wret
= push_leaf_right(trans
, root
, path
, data_size
, 0);
2232 wret
= push_leaf_left(trans
, root
, path
, data_size
, 0);
2238 /* did the pushes work? */
2239 if (btrfs_leaf_free_space(root
, l
) >= space_needed
)
2243 if (!path
->nodes
[1]) {
2244 ret
= insert_new_root(trans
, root
, path
, 1);
2251 slot
= path
->slots
[0];
2252 nritems
= btrfs_header_nritems(l
);
2253 mid
= (nritems
+ 1)/ 2;
2255 btrfs_item_key(l
, &disk_key
, 0);
2257 right
= btrfs_alloc_free_block(trans
, root
, root
->leafsize
,
2258 root
->root_key
.objectid
,
2259 root_gen
, disk_key
.objectid
, 0,
2261 if (IS_ERR(right
)) {
2263 return PTR_ERR(right
);
2266 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
2267 btrfs_set_header_bytenr(right
, right
->start
);
2268 btrfs_set_header_generation(right
, trans
->transid
);
2269 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
2270 btrfs_set_header_level(right
, 0);
2271 write_extent_buffer(right
, root
->fs_info
->fsid
,
2272 (unsigned long)btrfs_header_fsid(right
),
2275 write_extent_buffer(right
, root
->fs_info
->chunk_tree_uuid
,
2276 (unsigned long)btrfs_header_chunk_tree_uuid(right
),
2280 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
2281 BTRFS_LEAF_DATA_SIZE(root
)) {
2282 if (slot
>= nritems
) {
2283 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2284 btrfs_set_header_nritems(right
, 0);
2285 wret
= insert_ptr(trans
, root
, path
,
2286 &disk_key
, right
->start
,
2287 path
->slots
[1] + 1, 1);
2291 btrfs_tree_unlock(path
->nodes
[0]);
2292 free_extent_buffer(path
->nodes
[0]);
2293 path
->nodes
[0] = right
;
2295 path
->slots
[1] += 1;
2296 btrfs_mark_buffer_dirty(right
);
2300 if (mid
!= nritems
&&
2301 leaf_space_used(l
, mid
, nritems
- mid
) +
2302 space_needed
> BTRFS_LEAF_DATA_SIZE(root
)) {
2307 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
2308 BTRFS_LEAF_DATA_SIZE(root
)) {
2309 if (!extend
&& slot
== 0) {
2310 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2311 btrfs_set_header_nritems(right
, 0);
2312 wret
= insert_ptr(trans
, root
, path
,
2318 btrfs_tree_unlock(path
->nodes
[0]);
2319 free_extent_buffer(path
->nodes
[0]);
2320 path
->nodes
[0] = right
;
2322 if (path
->slots
[1] == 0) {
2323 wret
= fixup_low_keys(trans
, root
,
2324 path
, &disk_key
, 1);
2328 btrfs_mark_buffer_dirty(right
);
2330 } else if (extend
&& slot
== 0) {
2334 if (mid
!= nritems
&&
2335 leaf_space_used(l
, mid
, nritems
- mid
) +
2336 space_needed
> BTRFS_LEAF_DATA_SIZE(root
)) {
2342 nritems
= nritems
- mid
;
2343 btrfs_set_header_nritems(right
, nritems
);
2344 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
2346 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
2347 btrfs_item_nr_offset(mid
),
2348 nritems
* sizeof(struct btrfs_item
));
2350 copy_extent_buffer(right
, l
,
2351 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
2352 data_copy_size
, btrfs_leaf_data(l
) +
2353 leaf_data_end(root
, l
), data_copy_size
);
2355 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
2356 btrfs_item_end_nr(l
, mid
);
2358 for (i
= 0; i
< nritems
; i
++) {
2359 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
2362 if (!right
->map_token
) {
2363 map_extent_buffer(right
, (unsigned long)item
,
2364 sizeof(struct btrfs_item
),
2365 &right
->map_token
, &right
->kaddr
,
2366 &right
->map_start
, &right
->map_len
,
2370 ioff
= btrfs_item_offset(right
, item
);
2371 btrfs_set_item_offset(right
, item
, ioff
+ rt_data_off
);
2374 if (right
->map_token
) {
2375 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2376 right
->map_token
= NULL
;
2379 btrfs_set_header_nritems(l
, mid
);
2381 btrfs_item_key(right
, &disk_key
, 0);
2382 wret
= insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
2383 path
->slots
[1] + 1, 1);
2387 btrfs_mark_buffer_dirty(right
);
2388 btrfs_mark_buffer_dirty(l
);
2389 BUG_ON(path
->slots
[0] != slot
);
2392 btrfs_tree_unlock(path
->nodes
[0]);
2393 free_extent_buffer(path
->nodes
[0]);
2394 path
->nodes
[0] = right
;
2395 path
->slots
[0] -= mid
;
2396 path
->slots
[1] += 1;
2398 btrfs_tree_unlock(right
);
2399 free_extent_buffer(right
);
2402 BUG_ON(path
->slots
[0] < 0);
2405 BUG_ON(num_doubles
!= 0);
2412 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
2413 struct btrfs_root
*root
,
2414 struct btrfs_path
*path
,
2415 u32 new_size
, int from_end
)
2420 struct extent_buffer
*leaf
;
2421 struct btrfs_item
*item
;
2423 unsigned int data_end
;
2424 unsigned int old_data_start
;
2425 unsigned int old_size
;
2426 unsigned int size_diff
;
2429 slot_orig
= path
->slots
[0];
2430 leaf
= path
->nodes
[0];
2431 slot
= path
->slots
[0];
2433 old_size
= btrfs_item_size_nr(leaf
, slot
);
2434 if (old_size
== new_size
)
2437 nritems
= btrfs_header_nritems(leaf
);
2438 data_end
= leaf_data_end(root
, leaf
);
2440 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
2442 size_diff
= old_size
- new_size
;
2445 BUG_ON(slot
>= nritems
);
2448 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2450 /* first correct the data pointers */
2451 for (i
= slot
; i
< nritems
; i
++) {
2453 item
= btrfs_item_nr(leaf
, i
);
2455 if (!leaf
->map_token
) {
2456 map_extent_buffer(leaf
, (unsigned long)item
,
2457 sizeof(struct btrfs_item
),
2458 &leaf
->map_token
, &leaf
->kaddr
,
2459 &leaf
->map_start
, &leaf
->map_len
,
2463 ioff
= btrfs_item_offset(leaf
, item
);
2464 btrfs_set_item_offset(leaf
, item
, ioff
+ size_diff
);
2467 if (leaf
->map_token
) {
2468 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2469 leaf
->map_token
= NULL
;
2472 /* shift the data */
2474 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2475 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
2476 data_end
, old_data_start
+ new_size
- data_end
);
2478 struct btrfs_disk_key disk_key
;
2481 btrfs_item_key(leaf
, &disk_key
, slot
);
2483 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
2485 struct btrfs_file_extent_item
*fi
;
2487 fi
= btrfs_item_ptr(leaf
, slot
,
2488 struct btrfs_file_extent_item
);
2489 fi
= (struct btrfs_file_extent_item
*)(
2490 (unsigned long)fi
- size_diff
);
2492 if (btrfs_file_extent_type(leaf
, fi
) ==
2493 BTRFS_FILE_EXTENT_INLINE
) {
2494 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
2495 memmove_extent_buffer(leaf
, ptr
,
2497 offsetof(struct btrfs_file_extent_item
,
2502 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2503 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
2504 data_end
, old_data_start
- data_end
);
2506 offset
= btrfs_disk_key_offset(&disk_key
);
2507 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
2508 btrfs_set_item_key(leaf
, &disk_key
, slot
);
2510 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2513 item
= btrfs_item_nr(leaf
, slot
);
2514 btrfs_set_item_size(leaf
, item
, new_size
);
2515 btrfs_mark_buffer_dirty(leaf
);
2518 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2519 btrfs_print_leaf(root
, leaf
);
2525 int btrfs_extend_item(struct btrfs_trans_handle
*trans
,
2526 struct btrfs_root
*root
, struct btrfs_path
*path
,
2532 struct extent_buffer
*leaf
;
2533 struct btrfs_item
*item
;
2535 unsigned int data_end
;
2536 unsigned int old_data
;
2537 unsigned int old_size
;
2540 slot_orig
= path
->slots
[0];
2541 leaf
= path
->nodes
[0];
2543 nritems
= btrfs_header_nritems(leaf
);
2544 data_end
= leaf_data_end(root
, leaf
);
2546 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
2547 btrfs_print_leaf(root
, leaf
);
2550 slot
= path
->slots
[0];
2551 old_data
= btrfs_item_end_nr(leaf
, slot
);
2554 if (slot
>= nritems
) {
2555 btrfs_print_leaf(root
, leaf
);
2556 printk("slot %d too large, nritems %d\n", slot
, nritems
);
2561 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2563 /* first correct the data pointers */
2564 for (i
= slot
; i
< nritems
; i
++) {
2566 item
= btrfs_item_nr(leaf
, i
);
2568 if (!leaf
->map_token
) {
2569 map_extent_buffer(leaf
, (unsigned long)item
,
2570 sizeof(struct btrfs_item
),
2571 &leaf
->map_token
, &leaf
->kaddr
,
2572 &leaf
->map_start
, &leaf
->map_len
,
2575 ioff
= btrfs_item_offset(leaf
, item
);
2576 btrfs_set_item_offset(leaf
, item
, ioff
- data_size
);
2579 if (leaf
->map_token
) {
2580 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2581 leaf
->map_token
= NULL
;
2584 /* shift the data */
2585 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2586 data_end
- data_size
, btrfs_leaf_data(leaf
) +
2587 data_end
, old_data
- data_end
);
2589 data_end
= old_data
;
2590 old_size
= btrfs_item_size_nr(leaf
, slot
);
2591 item
= btrfs_item_nr(leaf
, slot
);
2592 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
2593 btrfs_mark_buffer_dirty(leaf
);
2596 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2597 btrfs_print_leaf(root
, leaf
);
2604 * Given a key and some data, insert an item into the tree.
2605 * This does all the path init required, making room in the tree if needed.
2607 int btrfs_insert_empty_items(struct btrfs_trans_handle
*trans
,
2608 struct btrfs_root
*root
,
2609 struct btrfs_path
*path
,
2610 struct btrfs_key
*cpu_key
, u32
*data_size
,
2613 struct extent_buffer
*leaf
;
2614 struct btrfs_item
*item
;
2622 unsigned int data_end
;
2623 struct btrfs_disk_key disk_key
;
2625 for (i
= 0; i
< nr
; i
++) {
2626 total_data
+= data_size
[i
];
2629 total_size
= total_data
+ (nr
- 1) * sizeof(struct btrfs_item
);
2630 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
2637 slot_orig
= path
->slots
[0];
2638 leaf
= path
->nodes
[0];
2640 nritems
= btrfs_header_nritems(leaf
);
2641 data_end
= leaf_data_end(root
, leaf
);
2643 if (btrfs_leaf_free_space(root
, leaf
) <
2644 sizeof(struct btrfs_item
) + total_size
) {
2645 btrfs_print_leaf(root
, leaf
);
2646 printk("not enough freespace need %u have %d\n",
2647 total_size
, btrfs_leaf_free_space(root
, leaf
));
2651 slot
= path
->slots
[0];
2654 if (slot
!= nritems
) {
2656 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
2658 if (old_data
< data_end
) {
2659 btrfs_print_leaf(root
, leaf
);
2660 printk("slot %d old_data %d data_end %d\n",
2661 slot
, old_data
, data_end
);
2665 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2667 /* first correct the data pointers */
2668 WARN_ON(leaf
->map_token
);
2669 for (i
= slot
; i
< nritems
; i
++) {
2672 item
= btrfs_item_nr(leaf
, i
);
2673 if (!leaf
->map_token
) {
2674 map_extent_buffer(leaf
, (unsigned long)item
,
2675 sizeof(struct btrfs_item
),
2676 &leaf
->map_token
, &leaf
->kaddr
,
2677 &leaf
->map_start
, &leaf
->map_len
,
2681 ioff
= btrfs_item_offset(leaf
, item
);
2682 btrfs_set_item_offset(leaf
, item
, ioff
- total_data
);
2684 if (leaf
->map_token
) {
2685 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2686 leaf
->map_token
= NULL
;
2689 /* shift the items */
2690 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
2691 btrfs_item_nr_offset(slot
),
2692 (nritems
- slot
) * sizeof(struct btrfs_item
));
2694 /* shift the data */
2695 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2696 data_end
- total_data
, btrfs_leaf_data(leaf
) +
2697 data_end
, old_data
- data_end
);
2698 data_end
= old_data
;
2701 /* setup the item for the new data */
2702 for (i
= 0; i
< nr
; i
++) {
2703 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
2704 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
2705 item
= btrfs_item_nr(leaf
, slot
+ i
);
2706 btrfs_set_item_offset(leaf
, item
, data_end
- data_size
[i
]);
2707 data_end
-= data_size
[i
];
2708 btrfs_set_item_size(leaf
, item
, data_size
[i
]);
2710 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
2711 btrfs_mark_buffer_dirty(leaf
);
2715 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
2716 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2719 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2720 btrfs_print_leaf(root
, leaf
);
2728 * Given a key and some data, insert an item into the tree.
2729 * This does all the path init required, making room in the tree if needed.
2731 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
2732 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
2736 struct btrfs_path
*path
;
2737 struct extent_buffer
*leaf
;
2740 path
= btrfs_alloc_path();
2742 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
2744 leaf
= path
->nodes
[0];
2745 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
2746 write_extent_buffer(leaf
, data
, ptr
, data_size
);
2747 btrfs_mark_buffer_dirty(leaf
);
2749 btrfs_free_path(path
);
2754 * delete the pointer from a given node.
2756 * If the delete empties a node, the node is removed from the tree,
2757 * continuing all the way the root if required. The root is converted into
2758 * a leaf if all the nodes are emptied.
2760 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
2761 struct btrfs_path
*path
, int level
, int slot
)
2763 struct extent_buffer
*parent
= path
->nodes
[level
];
2768 nritems
= btrfs_header_nritems(parent
);
2769 if (slot
!= nritems
-1) {
2770 memmove_extent_buffer(parent
,
2771 btrfs_node_key_ptr_offset(slot
),
2772 btrfs_node_key_ptr_offset(slot
+ 1),
2773 sizeof(struct btrfs_key_ptr
) *
2774 (nritems
- slot
- 1));
2777 btrfs_set_header_nritems(parent
, nritems
);
2778 if (nritems
== 0 && parent
== root
->node
) {
2779 BUG_ON(btrfs_header_level(root
->node
) != 1);
2780 /* just turn the root into a leaf and break */
2781 btrfs_set_header_level(root
->node
, 0);
2782 } else if (slot
== 0) {
2783 struct btrfs_disk_key disk_key
;
2785 btrfs_node_key(parent
, &disk_key
, 0);
2786 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, level
+ 1);
2790 btrfs_mark_buffer_dirty(parent
);
2795 * delete the item at the leaf level in path. If that empties
2796 * the leaf, remove it from the tree
2798 int btrfs_del_items(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
2799 struct btrfs_path
*path
, int slot
, int nr
)
2801 struct extent_buffer
*leaf
;
2802 struct btrfs_item
*item
;
2810 leaf
= path
->nodes
[0];
2811 last_off
= btrfs_item_offset_nr(leaf
, slot
+ nr
- 1);
2813 for (i
= 0; i
< nr
; i
++)
2814 dsize
+= btrfs_item_size_nr(leaf
, slot
+ i
);
2816 nritems
= btrfs_header_nritems(leaf
);
2818 if (slot
+ nr
!= nritems
) {
2820 int data_end
= leaf_data_end(root
, leaf
);
2822 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2824 btrfs_leaf_data(leaf
) + data_end
,
2825 last_off
- data_end
);
2827 for (i
= slot
+ nr
; i
< nritems
; i
++) {
2830 item
= btrfs_item_nr(leaf
, i
);
2831 if (!leaf
->map_token
) {
2832 map_extent_buffer(leaf
, (unsigned long)item
,
2833 sizeof(struct btrfs_item
),
2834 &leaf
->map_token
, &leaf
->kaddr
,
2835 &leaf
->map_start
, &leaf
->map_len
,
2838 ioff
= btrfs_item_offset(leaf
, item
);
2839 btrfs_set_item_offset(leaf
, item
, ioff
+ dsize
);
2842 if (leaf
->map_token
) {
2843 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2844 leaf
->map_token
= NULL
;
2847 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
2848 btrfs_item_nr_offset(slot
+ nr
),
2849 sizeof(struct btrfs_item
) *
2850 (nritems
- slot
- nr
));
2852 btrfs_set_header_nritems(leaf
, nritems
- nr
);
2855 /* delete the leaf if we've emptied it */
2857 if (leaf
== root
->node
) {
2858 btrfs_set_header_level(leaf
, 0);
2860 u64 root_gen
= btrfs_header_generation(path
->nodes
[1]);
2861 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
2864 wret
= btrfs_free_extent(trans
, root
,
2865 leaf
->start
, leaf
->len
,
2866 btrfs_header_owner(path
->nodes
[1]),
2872 int used
= leaf_space_used(leaf
, 0, nritems
);
2874 struct btrfs_disk_key disk_key
;
2876 btrfs_item_key(leaf
, &disk_key
, 0);
2877 wret
= fixup_low_keys(trans
, root
, path
,
2883 /* delete the leaf if it is mostly empty */
2884 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 4) {
2885 /* push_leaf_left fixes the path.
2886 * make sure the path still points to our leaf
2887 * for possible call to del_ptr below
2889 slot
= path
->slots
[1];
2890 extent_buffer_get(leaf
);
2892 wret
= push_leaf_left(trans
, root
, path
, 1, 1);
2893 if (wret
< 0 && wret
!= -ENOSPC
)
2896 if (path
->nodes
[0] == leaf
&&
2897 btrfs_header_nritems(leaf
)) {
2898 wret
= push_leaf_right(trans
, root
, path
, 1, 1);
2899 if (wret
< 0 && wret
!= -ENOSPC
)
2903 if (btrfs_header_nritems(leaf
) == 0) {
2905 u64 bytenr
= leaf
->start
;
2906 u32 blocksize
= leaf
->len
;
2908 root_gen
= btrfs_header_generation(
2911 wret
= del_ptr(trans
, root
, path
, 1, slot
);
2915 free_extent_buffer(leaf
);
2916 wret
= btrfs_free_extent(trans
, root
, bytenr
,
2918 btrfs_header_owner(path
->nodes
[1]),
2923 /* if we're still in the path, make sure
2924 * we're dirty. Otherwise, one of the
2925 * push_leaf functions must have already
2926 * dirtied this buffer
2928 if (path
->nodes
[0] == leaf
)
2929 btrfs_mark_buffer_dirty(leaf
);
2930 free_extent_buffer(leaf
);
2933 btrfs_mark_buffer_dirty(leaf
);
2940 * search the tree again to find a leaf with lesser keys
2941 * returns 0 if it found something or 1 if there are no lesser leaves.
2942 * returns < 0 on io errors.
2944 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
2946 struct btrfs_key key
;
2947 struct btrfs_disk_key found_key
;
2950 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, 0);
2954 else if (key
.type
> 0)
2956 else if (key
.objectid
> 0)
2961 btrfs_release_path(root
, path
);
2962 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
2965 btrfs_item_key(path
->nodes
[0], &found_key
, 0);
2966 ret
= comp_keys(&found_key
, &key
);
2973 * A helper function to walk down the tree starting at min_key, and looking
2974 * for nodes or leaves that are either in cache or have a minimum
2975 * transaction id. This is used by the btree defrag code, but could
2976 * also be used to search for blocks that have changed since a given
2979 * This does not cow, but it does stuff the starting key it finds back
2980 * into min_key, so you can call btrfs_search_slot with cow=1 on the
2981 * key and get a writable path.
2983 * This does lock as it descends, and path->keep_locks should be set
2984 * to 1 by the caller.
2986 * This honors path->lowest_level to prevent descent past a given level
2989 * returns zero if something useful was found, < 0 on error and 1 if there
2990 * was nothing in the tree that matched the search criteria.
2992 int btrfs_search_forward(struct btrfs_root
*root
, struct btrfs_key
*min_key
,
2993 struct btrfs_path
*path
, int cache_only
,
2996 struct extent_buffer
*cur
;
2997 struct btrfs_key found_key
;
3004 cur
= btrfs_lock_root_node(root
);
3005 level
= btrfs_header_level(cur
);
3006 path
->nodes
[level
] = cur
;
3007 path
->locks
[level
] = 1;
3009 if (btrfs_header_generation(cur
) < min_trans
) {
3014 nritems
= btrfs_header_nritems(cur
);
3015 level
= btrfs_header_level(cur
);
3016 bin_search(cur
, min_key
, level
, &slot
);
3018 /* at level = 0, we're done, setup the path and exit */
3021 path
->slots
[level
] = slot
;
3022 btrfs_item_key_to_cpu(cur
, &found_key
, slot
);
3026 * check this node pointer against the cache_only and
3027 * min_trans parameters. If it isn't in cache or is too
3028 * old, skip to the next one.
3030 while(slot
< nritems
) {
3033 struct extent_buffer
*tmp
;
3034 blockptr
= btrfs_node_blockptr(cur
, slot
);
3035 gen
= btrfs_node_ptr_generation(cur
, slot
);
3036 if (gen
< min_trans
) {
3043 tmp
= btrfs_find_tree_block(root
, blockptr
,
3044 btrfs_level_size(root
, level
- 1));
3046 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
3047 free_extent_buffer(tmp
);
3051 free_extent_buffer(tmp
);
3055 * we didn't find a candidate key in this node, walk forward
3056 * and find another one
3058 if (slot
>= nritems
) {
3059 ret
= btrfs_find_next_key(root
, path
, min_key
, level
,
3060 cache_only
, min_trans
);
3062 btrfs_release_path(root
, path
);
3068 /* save our key for returning back */
3069 btrfs_node_key_to_cpu(cur
, &found_key
, slot
);
3070 path
->slots
[level
] = slot
;
3071 if (level
== path
->lowest_level
) {
3073 unlock_up(path
, level
, 1);
3076 cur
= read_node_slot(root
, cur
, slot
);
3078 btrfs_tree_lock(cur
);
3079 path
->locks
[level
- 1] = 1;
3080 path
->nodes
[level
- 1] = cur
;
3081 unlock_up(path
, level
, 1);
3085 memcpy(min_key
, &found_key
, sizeof(found_key
));
3090 * this is similar to btrfs_next_leaf, but does not try to preserve
3091 * and fixup the path. It looks for and returns the next key in the
3092 * tree based on the current path and the cache_only and min_trans
3095 * 0 is returned if another key is found, < 0 if there are any errors
3096 * and 1 is returned if there are no higher keys in the tree
3098 * path->keep_locks should be set to 1 on the search made before
3099 * calling this function.
3101 int btrfs_find_next_key(struct btrfs_root
*root
, struct btrfs_path
*path
,
3102 struct btrfs_key
*key
, int lowest_level
,
3103 int cache_only
, u64 min_trans
)
3105 int level
= lowest_level
;
3107 struct extent_buffer
*c
;
3109 while(level
< BTRFS_MAX_LEVEL
) {
3110 if (!path
->nodes
[level
])
3113 slot
= path
->slots
[level
] + 1;
3114 c
= path
->nodes
[level
];
3116 if (slot
>= btrfs_header_nritems(c
)) {
3118 if (level
== BTRFS_MAX_LEVEL
) {
3124 btrfs_item_key_to_cpu(c
, key
, slot
);
3126 u64 blockptr
= btrfs_node_blockptr(c
, slot
);
3127 u64 gen
= btrfs_node_ptr_generation(c
, slot
);
3130 struct extent_buffer
*cur
;
3131 cur
= btrfs_find_tree_block(root
, blockptr
,
3132 btrfs_level_size(root
, level
- 1));
3133 if (!cur
|| !btrfs_buffer_uptodate(cur
, gen
)) {
3136 free_extent_buffer(cur
);
3139 free_extent_buffer(cur
);
3141 if (gen
< min_trans
) {
3145 btrfs_node_key_to_cpu(c
, key
, slot
);
3153 * search the tree again to find a leaf with greater keys
3154 * returns 0 if it found something or 1 if there are no greater leaves.
3155 * returns < 0 on io errors.
3157 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
3161 struct extent_buffer
*c
;
3162 struct extent_buffer
*next
= NULL
;
3163 struct btrfs_key key
;
3167 nritems
= btrfs_header_nritems(path
->nodes
[0]);
3172 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, nritems
- 1);
3174 btrfs_release_path(root
, path
);
3175 path
->keep_locks
= 1;
3176 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3177 path
->keep_locks
= 0;
3182 nritems
= btrfs_header_nritems(path
->nodes
[0]);
3184 * by releasing the path above we dropped all our locks. A balance
3185 * could have added more items next to the key that used to be
3186 * at the very end of the block. So, check again here and
3187 * advance the path if there are now more items available.
3189 if (nritems
> 0 && path
->slots
[0] < nritems
- 1) {
3194 while(level
< BTRFS_MAX_LEVEL
) {
3195 if (!path
->nodes
[level
])
3198 slot
= path
->slots
[level
] + 1;
3199 c
= path
->nodes
[level
];
3200 if (slot
>= btrfs_header_nritems(c
)) {
3202 if (level
== BTRFS_MAX_LEVEL
) {
3209 btrfs_tree_unlock(next
);
3210 free_extent_buffer(next
);
3213 if (level
== 1 && path
->locks
[1] && path
->reada
)
3214 reada_for_search(root
, path
, level
, slot
, 0);
3216 next
= read_node_slot(root
, c
, slot
);
3217 if (!path
->skip_locking
) {
3218 WARN_ON(!btrfs_tree_locked(c
));
3219 btrfs_tree_lock(next
);
3223 path
->slots
[level
] = slot
;
3226 c
= path
->nodes
[level
];
3227 if (path
->locks
[level
])
3228 btrfs_tree_unlock(c
);
3229 free_extent_buffer(c
);
3230 path
->nodes
[level
] = next
;
3231 path
->slots
[level
] = 0;
3232 if (!path
->skip_locking
)
3233 path
->locks
[level
] = 1;
3236 if (level
== 1 && path
->locks
[1] && path
->reada
)
3237 reada_for_search(root
, path
, level
, slot
, 0);
3238 next
= read_node_slot(root
, next
, 0);
3239 if (!path
->skip_locking
) {
3240 WARN_ON(!btrfs_tree_locked(path
->nodes
[level
]));
3241 btrfs_tree_lock(next
);
3245 unlock_up(path
, 0, 1);
3250 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
3251 * searching until it gets past min_objectid or finds an item of 'type'
3253 * returns 0 if something is found, 1 if nothing was found and < 0 on error
3255 int btrfs_previous_item(struct btrfs_root
*root
,
3256 struct btrfs_path
*path
, u64 min_objectid
,
3259 struct btrfs_key found_key
;
3260 struct extent_buffer
*leaf
;
3264 if (path
->slots
[0] == 0) {
3265 ret
= btrfs_prev_leaf(root
, path
);
3271 leaf
= path
->nodes
[0];
3272 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
3273 if (found_key
.type
== type
)